Total hip replacement for adults with unreduced congenital dislocation presents a difficult problem because soft-tissue contractures usually prevent sitting at the normal anatomical level. Extensive soft-tissue division or a high-level acetabulum leads to reduced function and poor fixation of the components. We describe a new technique for hip replacement in such cases. The shortened abductors and flexors are released proximally and excision of the upper third of the ilium allows them to be repaired without tension, while providing bone graft to reconstruct the acetabular roof. We report 12 such replacements in 10 patients with good results and few early complications.

Fracture of the polyethylene acetabular cup is a rare late complication of total hip replacement. Five cases are reported. In each one this followed a fall, and involved a Muller arthroplasty which had previously been symptomless. It is postulated that ridges or other irregularities of bone, produced by keying holes, could lead to areas of thin cement and potential weakness of support for the cup.